A novel measurement that might provide information on the secondary and tertiary structure of biomolecules is the disruption of the structure through the slow application of mechanical forces. The case of pulling apart the two strands of DNA and hence ~unzipping~ the helix has been analyzed by Thompson and Siggia, ~96 and estimates of the magnitudes of the relevant forces given. Recently we have examined the experimental possibilities of detecting such forces and concluded that with an advanced experimental apparatus the breaking of individual base pairs should be resolvable. The apparatus would include differential interferometric detection of the bending of an AFM cantilever and utilize a piezoelectric arm to separate the two strands.